The present invention relates to a switchgear apparatus for power supply, more particularly, to a hybrid (xe2x88x92type) gas insulation switchgear apparatus with improvement in arrangement of various constitutional members or units including a breaker.
A substation layout includes, as representative examples, one shown in a single line (connection) diagram of a single bus of FIG. 20, and one shown in a single line (connection) diagram of one and half bus (1xc2xd) of FIG. 21. In FIGS. 20 and 21, the switchgear apparatus corresponding to a portion surrounded by short dash-lines have similar structures, respectively, in which a breaker 20 and disconnectors 30 disposed on both ends of the breaker 20 are electrically connected in series. Reference numeral 90 denotes a transformer.
In general, in air substations, since bus and steel tower have long service lives, the bus or steel tower is less exchanged or replaced at a time of exchanging or replacing the switchgear apparatus. In this viewpoint, usually, the switchgear apparatus is replaced by another one having high performance and high reliability, while effectively utilizing an air insulating bus and the like already set in place.
In order to meet such needs, there has so far been proposed a hybrid (xe2x88x92type) gas insulation switchgear apparatus. As an example of hybrid gas insulation switchgear apparatus, a general hybrid gas insulation switchgear apparatus will be explained hereunder with reference to an illustration of FIG. 22. The illustrated hybrid gas insulation switchgear apparatus corresponds to a portion shown with a dash-line portion in the single-line connection diagrams in FIG. 20 and FIG. 21 and is applicable to a double bus type bus connection, though not illustrated.
In other words, the breaker 20 in the hybrid gas insulation switchgear apparatus is operated by an operating mechanism 28 and is equipped with a stationary side electrode 21 and a movable side electrode 22 accommodated in an enclosure 81. The breaker 20 is provided with both side portions to which disconnectors 30a, 30b accommodated in enclosures 82a, 82b are provided. The disconnectors 30a, 30b are constituted to be capable of being opened or closed (switched) by an operating mechanism 33. The enclosures 82a, 82b are supported by a frame. The breaker 20 and the disconnectors 30a, 30b are connected through an adapter conductor 100 accommodated in a vessel.
On the enclosures 82a, 82b accommodating the disconnectors 30a, 30b, there are fitted the bushings 1a, 1b through the insulating spacers 63, respectively, and the conductors 11a, 11b of the inside bushings are connected to the disconnectors 30a, 30b through conductors provided on the insulating spacers 63. Further, an earth switches 4a, 4b are disposed between the adapter conductor 100 and the disconnectors 30a, 30b so as to be opened or closed by an operating mechanism 43. Reference numerals 70a, 70b denote current transformers.
However, in the conventional hybrid gas insulation switchgear apparatus of the structures mentioned above, the breaker 20 and the disconnectors 30a, 30b are accommodated respectively independently in the separate enclosures 81, 82a, and 82b. Accordingly, the entire size of the device is apt to become larger, the weight thereof is also apt to become heavier, and product price becomes higher.
An object of the present invention is to substantially eliminate defects or drawbacks encountered in the prior art mentioned above and to provide a hybrid (type) gas insulation switchgear apparatus or system having a compact and simple structure, which can be easily maintained.
This and other objects can be achieved according to the present invention by providing a hybrid gas insulation switchgear apparatus comprising:
an enclosure in which an insulating gas is sealed;
a bushing unit provided for the enclosure;
a breaker unit disposed inside the enclosure;
a disconnector unit disposed inside the enclosure and including disconnectors to be connected electrically in series to both sides of the breaker unit;
an earth switch unit disposed inside the enclosure and including earth switches disposed between the breaker unit and the disconnectors, respectively, the earth switches being provided with main pole side electrodes disposed on the side of the breaker unit; and
a current transformer unit mounted to the enclosure,
the bushing unit including bushings each having a conductor connected to an electrode in the disconnector on a side opposite to the breaker.
According to this aspect, the breaker unit, the disconnector unit and the earth switch unit are accommodated in a single enclosure, and therefore, it is not necessary to use a long connecting conductors such as that required in a prior art. Accordingly, it is possible to realize a hybrid gas insulation switchgear apparatus having compact and light-weight size.
Hereunder, preferred embodiments of the present invention and their advantageous functions and effects will be described.
The conductor of the bushing and the electrode of the disconnector are supported and fixed in the enclosure by an insulating member having substantially a cylindrical or columnar shape.
In the above structure, since the conductor of the bushing is directly connected to one side electrode of the disconnector and it is supported in the enclosure by the cylindrical or columnar insulator, it is possible to reduce the number of parts of the connector, thereby making it possible to simplify the assembly working of the apparatus.
A gas space between the enclosure and the bushing unit is sectioned by an insulating member having substantially conical shape, and the electrode disposed on the side opposite to the breaker unit in the disconnector is supported by the insulating member.
According to this arrangement, the workability in the checking or inspecting time can be improved.
The enclosure is provided with at least one branch portion, the bushing unit is mounted to the branch portion and at least a set of disconnector and earth switch is accommodated in the branch portion.
In this structure, since the disconnector and the earth switch are accommodated in the branch portion, the direct exposure of the disconnector and the earth switch to the hot gas blown from the breaker at a time of breaking a large current can be prevented. Accordingly, it is possible to improve safeness. In addition, it is possible to shorten the size of the enclosure for accommodating the breaker.
The enclosure is disposed in a perpendicular direction with respect to a ground surface.
According to this arrangement, the installation area of the switchgear apparatus in the horizontal direction can be widely reduced, and moreover, the insulation distance to the ground of the bushing unit can be secured easily by the perpendicular arrangement of the enclosure.
Two branch portions are provided in different height levels. The direct exposure of the hot gas from the breaker unit at the time of the large current breaking can be prevented by this arrangement.
The two branch portions are provided symmetrically with respect to an axis of the enclosure at mutually different angles.
According to this arrangement, even if the portion accommodating the breaker unit in the enclosure is shortened, the air insulation distance of the bushing unit can be secured, and it is possible to realize the compact structure of the switchgear apparatus.
The breaker unit is driven by an operating mechanism provided on an extension of an axis of the electrode for the breaker unit.
According to this arrangement, it is possible to transmit the driving force of the operating mechanism linearly to the breaker unit, thus simplifying the structure of the driving unit.
The two branch portions are provided in perpendicular direction to the axis of the enclosure. Accordingly, the entire structure of the switchgear apparatus can be made compact and simplified.
Two sets of the earth switches and disconnectors are provided horizontally and in parallel to each other.
According to this structure, since it is possible to save the spaces in the longitudinal direction of the earth switch and the disconnector and shorten the length of the enclosure, the compact structure of the switchgear apparatus can be realized.
The disconnectors are driven by a single operating mechanism. Accordingly, the switchgear apparatus can be also made compact and the control system can be simplified.
A driving force transmitting device for transmitting a driving force of the operating mechanism to the two disconnectors is accommodated in the enclosure. Thus, the gas-tightness to the insulating gas can be easily secured.
The enclosure is disposed in a horizontal direction with respect to the ground level, two branch portions accommodating the disconnectors are provided on an upper portion of the enclosure, an operating mechanism is set at substantially a central portion of the branch portions on the upper portion of the enclosure, and the two disconnectors disposed inside the branch portions and the operating mechanism are connected through an operating rod.
According to this arrangement, since the driving force transmission route can be provided on the straight line, the switchgear apparatus can be simplified in arrangement.
Furthermore, the disconnector unit and the earth switch unit are provided to be driven by a single operating mechanism.
In this arrangement, it is possible to curtail the number of the operating mechanisms, and therefore, it becomes possible to make simplified the entire structure of the switchgear.
The nature and further characteristic features of the present invention will be made more clear from the following descriptions made with reference to the accompanying drawings.